Pliers for external circlips



March 5, 1968 M. J. L. DEGUY PLIERS FOR EXTERNAL CIRCLIPS Fil'ed Feb. 10, 1966' 3,371,401 I PLIERS FOR EXTERNAL 'CIRCLIPS Michel Jean Louis Deguy, Luzy-snr-Marne, Haute-Marne,

France, assignor to Deguy-Conge & Cie, Luzy-sur- Marne, Haute Marne, France v Filed Feb. 10, 1966, Ser. No. 526,527 Claims'priority, application France, Feb. 17, 1965, 5,860, Patent 1,433,504 9'Claims. (Cl. 29-429) ABSTRACT OF THE DISCLOSURE Circlips pliers provided with opening limiting jaws the spacing of which is adjustable in such a manner as to permit an instant and easy adjustment thereof with a single shifting of a slideway by the thumb of the hand which holds the pliers. The branches and the jaws are hingedly connected by two pins which engage respectively with two oblique symmetrical slots formed in the slideway. Furthermore, this slideway serves as guide means insuring symmetricalspreading of the branches.

Already well known are the expanding type of pliers used for fittingor removing external circlips with circular or semi-circular lobes. Such pliers terminate in pointed nose-pieces which can be inserted into holes provided in circular lobes or into notches provided in semicircular lobes.

Certain pliers of this kind are equipped with an adjustable set-screw which is mounted on one of the branches of the pliers and serves to limit the degree of opening thereof in order not to exceed the elastic limit of the circlip. Such adjustments, however, can be made neither conveniently nor rapidly and, furthermore, the circlip is not suitably restrained to prevent possible warping and consequent additional fatigue to the circlip metal.

The pliers according to this invention overcome these drawbacks and offer additional advantages. They incorporate the following features:

(a) Lateral jaws which flank the nose of the pliers and serve both to limit the degree of opening and to restrain the circlip lobes in order to prevent warping.

(b) The spacing between the jaws is adjustable to enable the pliers to be adapted to diflferent circlip diameters.

(c) Guide means insure symmetrical spreading of the nose-pieces and spacing of the jaws with respect to the centerline of the pliers.

(d) A single slideway serves both as the guide means referred to and for adjustment of the jaws, this slideway being instantly operable with the thumb while the pliers are held in the palm of the hand.

(e) The pliers can also be used for lobeless circlips by reason of channels formed in the tips of the jaws.

The description which follow with reference to the accompanying non-limitative exemplary drawings will give a clear understanding of how the invention can be carried into practice.

In the drawings:

FIG. 1 is a top view of the pliers according to the invention, the guiding and adjustment slide being shown in an intermediate position;

FIG. 2 is a corresponding bottom view;

FIGS. 3, 4 and are examples of three different types of circlips capable of being opened by the pliers according to the invention;

FIG. 6 is a parital perspective view showing the manner in which the pliers are used to fit a lobed circlip;

FIG. 7 is an end view on an enlarged scale showing the circlip opened to the maximum; and

FIG. 8 shows the way in which the pliers are used in the case of lobeless circlips.

eed O As is more clearly apparent from FIG. 2, two jaws 1a, 1b are pivotally interconnected about a pin 2, whereby they can spread apart to a varying extent.

Each jaw is formed of two parallel plates between which extends the outer end of one of the two branches 3a (or 3b) of the pliers, and said two plates are united over their outer portion 4a (or 4b).

Each branch of the pliers is rockably mounted, at a point adjacent its nose-piece, about a pin 5a (or 5b) which is carried by the corresponding jaw between the two plates thereof and caused to project slightly on the front side of the pliers whereby to extend through an associated oblique slot 6a (or 612) formed in a slideway 7 Which is restrained on the front side by heads formed on the pins 5a, 5b. The two slots 6a, 6b are formed symmetrically with respect to the slideway centerline, which in turn coincide with the pliers centerline.

The nose-pieces 8a, 8b of the pliers are formed with fine points urged against against each other by a U-spring 9 which extends between the two plates of each jaw 1a, 115, over their mutual hinge pin 2, and the ends of which are restrained inside the two handle portions, the branches 3a, 3b being accordingly formed with inwardly facing channel sections.

The tips of the nose-pieces and the tips of the jaws are substantially level with one another.

In addition to the two oblique symmetrical slots 6a, 6b, slideway 7 has formed therein two centrally aligned slots 10 and 11. The jaw hinge-pin 2 is extended to slidably engage in slot 10 and terminates in a wider head portion which restrains the slideway.

Slidably engaging in slot 11 is the common pivot 12 of two links 13a, 13b of equal length forming a symmetrical V, the ends remote from pin 12 of which are pivotally connected at 14a and 14b adjacent the ends of the grip portions of branches 3a, 3b respectively.

Slot 10 limits the displacement of the slideway, and the limit positions of pin 2 in slot 10 also determine the limit positons of pins 511, 5b in oblique slots 6a, 6b, with one of these limit positions defining the minimum spacing between jaws 1a, 1b and the other the maximum spacing thereof, as is clearly shown in FIG. 1. Slot 11 extends to a sufficient degree to either side of pin 12 to permit free movement of the branches 3a, 3b whatever the position of the slideway.

It will be manifest that the arrangement described hereinbefore for the slideway slots and their associated guided pins will insure constant symmetry of the jaws and branches of the pliers with respect to the slideway centerline.

In order to enable slideway 7 to be more readily displaceable with the thumb while the grip portions of the branches are held in the palm of the hand, it is formed with a ribbed or knurled raised portion 15 conveniently positioned between pin 2 and pins 50, 51;.

FIGS. 3, 4 and 5 illustrate three commonly used types of expandible circlips which can readily be manipulated with the pliers according to the invention, to wit a circlip 16 with circular lobes, a circlip 17 with semicircular lobes and a circlip 18 devoid of lobes.

FIGS. 6 and 7 show the way in which a lobed circlip 16 can be positioned in a groove 19 formed on a cylindrical part 20 such as a shaft. Having first adjusted the jaws 1a, 1b to the required spacing, points 8a, 8b of the pliers are inserted into the lobe holes after the branches 3a, 3b have been squeezed to match the gap between said points to the spacing between the holes, following which, by further squeezing of the branches of the pliers, the pionts are spread apart until the lobes of the circlip contact the tips of the jaws, as shown in FIG. 7. In order to provide more positive retention for the lobes, the jaw tips 4a, 4b are formed with slight inwardly facing concavities, whereby each lobe is gripped between two thrust points. This prevents circlip 16 from warping and its. degree of opening is limited by the jaws. It can then be threaded over the part 20 to a point level with groove 19 and can then be allowed to reclose inside the groove by releasing the branches of the pliers. A circlip with semi circular lobes such as circlip 17 can be fitted in the same way. The operations for removing the circlip are identical.

FIG. 8 shows how the pliers according to the invention can be used with a lobeless expandible circlip 18 through the provision of two notches, or the like, formed at the tips of the jaws, along the centerplane thereof. The ring is engaged into these notches which, while constraining the circlip to remain in its own plane to prevent it from warping, guide the ends of the circlip into contact with the points 8a, 8b of the pliers.

It goes without saying that many changes and substitutions of parts may be made to the specific form of embodiment hereinbefore described, without departing from the scope of the invention. Thus, instead of having a fixed. head, pin 2 could terminate in a threaded portion on towhich could be screwed a wing-nut or a knurled nut for enabling the slideway to be fixedly secnred after adjustment, as for instance in the case of serial operations on circlips of the same size. Further, instead of causing the jaws to be guided in the oblique slots 6a, 61) by means of the hinge pins a, 5b on the branches of the pliers, recourse could be had to studs independent of said pins; also, the two branches of the pliers could be hinged on to each other instead of being hinged one on each jaw, and so on. It would appear, however, that the specific form of embodiment described hereinabove represents the simplest arrangement.

What I claim is:

1. Pliers for fitting and removing external expandible circlips provided with yieldably spaced ends, said pliers comprising a pair of branches including grips and tips mounted on said grips and adapted to engage said circlips ends, a pair of jaws having tips positioned respectively outwardly of the first said pair of tips, a central slideway having a longitudinal axis, two pins supported by said slideway each of which hingedly connect one of said jaws to the related branch, means for moving said jaws selectively toward or away from each other and means for maintaining said pair of branches and said pair of jaws symmetrical with respect to said slideway axis, said means for moving the jaws comprising a portion in said slideway provided with two oblique slots and studs connected with said jaws and engaged in said oblique slots, and means for displacing said slideway and thereby said portion along said axis.

2. Pliers according to claim 1 wherein said studs are extensions of said pins.

3. Fliers according to claim 2 further comprising and wherein said jaws are hingedly interconnected on a first common hinge-pin.

4. Eliers according to claim 2 wherein said symmetry maintaining means comprises a pair of links of equal length, symmetrical with respect to said axis, hingedly interconnected on a second hinge-pin and having their opposite ends pivotally connected respectively to said grips, a first slot being formed in said slideway on said axis and engaging with said second hinge-pin.

5. Pliers according to claim 3 wherein said symmetry maintainingmeans comprises a pair of links of equal length, symmetrical with respect to said axis, hingedly interconnected on a second hinge-pin and having their opposite ends pivotally connected respectively to said grips, a first slot and a second slot being formed in said slideway on said axis and engaging respectively with said second and first hinge-pin.

6. Pliers according to claim 5 wherein said slideway is selectively fixed in position by a not on a threaded end portion on said first hinge-pin extending through said second slot.

7. Pliers according to claim 1 wherein said slideway displacing means comprises a ribbed raised portion on said slideway adapted to be shifted by the thumb of the hand of the user holding the pliers.

8. Pliers according to claim 1 wherein said jaw tips are provided with slight inward facing concavities.

' 9. Pliers-according to claim 1 wherein said jaw tips are provided along their centerplane with inward facing channels.

References Cited UNITED STATES PATENTS 1,995,165 3/1935 Anderson 29223 2,455,165 11/1948 Feitl 29229 2,553,620 5/1951 Yeazell 29229 X 3,050,841 8/1962 Essclstyn 29--268 OTHELL M. SIMPSON, Primary Examiner.

WILLIAM FELDMAN, Examiner.

J. C. PETERS, Assistant Examiner. 

